Safi is a leader of the progressive Muslim movement,[6] which he defines as encompassing

a number of themes: striving to realize a just and pluralistic society through a critical engagement with Islam, a relentless pursuit of social justice, an emphasis on gender equality as a foundation of human rights, and a vision of religious and ethnic pluralism.[7]

After September 11, 2001 Safi was publicly critical of the intolerance and violence among Muslims that inspired the attacks, reminding Muslims that their role lay in "calling both Muslims and Americans to the highest good of which we are capable."[5]

Safi's book Progressive Muslims (2003) contains a diverse collection of essays by and about progressive Muslims. He is one of a number of progressive scholars of Islam in the early 21st century whose work has described for Western readers the diverse range of Muslim thought in the last half of the 20th century.[8] As such, he has been described by Kevin Eckstrom, editor-in-chief of the Religion News Service, as "on the front edge of a generation of scholars who, with one foot in both worlds, are trying to explain Islam and the West to each other."[4]

Safi was one of the co-founders of the Progressive Muslim Union (PMU-NA).[9] He resigned from PMU in 2005, but he continues to support progressive interpretations of Islam outside of PMU.